1. Field of the Invention
The present invention relates in general to an apparatus and method for diagnosing antennas using switches, and more particularly to an apparatus and method for diagnosing antennas using switches, wherein a system is configured in such a manner that a plurality of switches determine a data flow of a signal for test, so that the antenna diagnosing apparatus can be simplified in circuitry construction and accurately diagnose the performance of the antennas without being subject to any error.
2. Description of the Prior Art
FIG. 1 is a functional block diagram showing the construction of a conventional antenna diagnosing apparatus. As shown in this drawing, the conventional antenna diagnosing apparatus comprises a key input unit 1, controller 2, transmission/reception block 3, first 4-port directional coupler 4, transmission/reception antenna 5, switch 6, first comparator 7, first amplifier 8, second 4-port directional coupler 9, third 4-port directional coupler 10, reception dedicated antenna 11, second amplifier 12, third amplifier 13 and second comparator 14.
The operation of the conventional antenna diagnosing apparatus with the above-mentioned construction will hereinafter be described with reference to FIG. 1.
First, if the user selects a transmission/reception antenna test mode through the key input unit 1, then the controller 2 outputs a switch control signal to the switch 6 such that a terminal a of the switch 6 is connected to a terminal b thereof. The controller 2 further outputs a transmission control signal to the transmission/reception block 3. In response to the transmission control signal from the controller 2, the transmission/reception block 3 outputs a radio frequency (referred to hereinafter as xe2x80x9cRFxe2x80x9d) signal for test to the transmission/reception antenna 5. At this time, the first 4-port directional coupler 4 sets up a first path along which the test RF signal from the transmission/reception block 3 is transferred to the first comparator 7 through the transmission/reception antenna 5 and a second path along which the test RF signal from the transmission/reception block 3 is transferred to the first comparator 7 directly, not through the transmission/reception antenna 5. Then, the first comparator 7 compares the level of the test RF signal returned via the transmission/reception antenna 5 with that of the test RF signal returned directly, not via the transmission/reception antenna 5, to measure a standing wave ratio of the transmission/reception antenna 5, which is used to diagnose a faulty state of the transmission/reception antenna 5. Herein, the standing wave ratio of the antenna signifies a ratio of the level of an RF signal transmitted through the antenna to the level of an RF signal not transmitted through the antenna but reflected into the system. As a result, the state of the antenna can be diagnosed on the basis of the standing wave ratio of the antenna.
On the other hand, if the user selects a reception dedicated antenna test mode through the key input unit 1, then the controller 2 outputs a switch control signal to the switch 6 such that the terminal a of the switch 6 is connected to a terminal c thereof. The controller 2 further outputs a transmission control signal to the transmission/reception block 3. In response to the transmission control signal from the controller 2, the transmission/reception block 3 outputs an RF signal for test to the reception dedicated antenna 11. At this time, the first 4-port directional coupler 4 and second 4-port directional coupler 9 cooperate to set up a path along which the test RF signal from the transmission/reception block 3 is transferred only to the reception dedicated antenna
Upon receiving the test RF signal from the transmission/reception block 3 via the first 4-port directional coupler 4 and switch 6, the first amplifier 8 amplifies the received test RF signal to a predetermined level and then outputs the amplified test RF signal to the reception dedicated antenna 11. At this time, the third 4-port directional coupler 10 sets up a first path along which the amplified test RF signal from the first amplifier 8 is transferred to the second comparator 14 through the reception dedicated antenna 11 and a second path along which the amplified test RF signal from the first amplifier 8 is transferred to the second comparator 14 directly, not through the reception dedicated antenna 11. The second amplifier 12 amplifies the test RF signal returned via the reception dedicated antenna 11 to a predetermined level and then outputs the amplified test RF signal to the second comparator 14. The third amplifier 13 amplifies the test RF signal returned directly, not via the reception dedicated antenna 11, to a predetermined level and then outputs the amplified test RF signal to the second comparator 14. Then, the second comparator 14 compares the level of the amplified test RF signal from the second amplifier 12 with that of the amplified test RF signal from the third amplifier 13 and measures a standing wave ratio of the reception dedicated antenna 11 in accordance with the compared result. Accordingly, a faulty operation of the reception dedicated antenna 11 is diagnosed on the basis of the measured standing wave ratio.
However, the above-described conventional antenna diagnosing apparatus is disadvantageous in that additional components such as a plurality of 4-port directional couplers and a plurality of amplifiers are used to implement a system, resulting in a complexity in circuitry construction and an increase in manufacturing cost. Further, there is a high possibility that data errors will occur when a plurality of 4-port directional couplers determine the flow of a test RF signal, thereby making it impossible to accurately measure a standing wave ratio of an antenna.
Therefore, the present invention has been made in view of the above problems, and it is an object of the present invention to provide an apparatus and method for diagnosing antennas using switches, wherein a system is configured in such a manner that a plurality of switches determine a data flow of a signal for test, thereby allowing the antenna diagnosing apparatus to be so simplified in circuitry construction that it can be easy to manufacture at low cost, and to accurately measure standing wave ratios of the antennas without being subject to any error, so as to accurately diagnose the performance of the antennae.
In accordance with one aspect of the present invention, the above and other objects can be accomplished by a provision of an apparatus for diagnosing states of a transmission/reception antenna and a reception dedicated antenna using first to third switches, comprising key input means for generating a transmission/reception antenna test mode signal or reception dedicated antenna test mode signal if the user selects a transmission/reception antenna test mode or reception dedicated antenna test mode to diagnose the state of the transmission/reception antenna or reception dedicated antenna; control means for generating an oscillator operation control signal and a first test mode switching control signal in response to the transmission/reception antenna test mode signal from the key input means and the oscillator operation control signal and a second test mode switching control signal in response to the reception dedicated antenna test mode signal from the key input means, respectively; standing wave ratio detection means for generating a radio frequency signal for test to the transmission/reception antenna or reception dedicated antenna in response to the oscillator operation control signal from the control means, comparing the level of the test radio frequency signal returned via the transmission/reception antenna or reception dedicated antenna with a reference radio frequency power level, measuring a standing wave ratio of the transmission/reception antenna or reception dedicated antenna in accordance with the compared result and sending an alarm signal for antenna fault notification to a base transceiver station if the measured standing wave ratio is lower than a reference level for fault determination; the first switch connecting the standing wave ratio detection means to the transmission/reception antenna in response to the first test mode switching control signal from the control means and the standing wave ratio detection means to the reception dedicated antenna in response to the second test mode switching control signal from the control means, respectively; the second switch connecting the standing wave ratio detection means to the transmission/reception antenna in response to the first test mode switching control signal from the control means and a receiver of the base transceiver station to the transmission/reception antenna in response to a normal mode switching control signal from the control means, respectively; and the third switch connecting the standing wave ratio detection means to the reception dedicated antenna in response to the second test mode switching control signal from the control means and the receiver of the base transceiver station to the reception dedicated antenna in response to the normal mode switching control signal from the control means, respectively.
In accordance with another aspect of the present invention, there is provided a method for diagnosing states of a transmission/reception antenna and a reception dedicated antenna using first to third switches, comprising the steps of a) allowing a controller to determine whether the user selects a transmission/reception antenna test mode or reception dedicated antenna test mode through a key input unit; b) allowing the controller to output a first test mode switching control signal to the first switch and second switch if the user selects the transmission/reception antenna test mode through the key input unit at the step a), so as to connect the transmission/reception antenna to a standing wave detector; c) allowing an oscillator to generate a radio frequency signal for test to the transmission/reception antenna in response to an oscillator operation control signal from the controller; d) allowing the standing wave ratio detector to compare the level of the test radio frequency signal from the oscillator returned via the transmission/reception antenna with a reference radio frequency power level and measure a standing wave ratio of the transmission/reception antenna in accordance with the compared result; e) allowing the standing wave ratio detector to compare the measured standing wave ratio of the transmission/reception antenna with a reference level for fault determination to determine whether the measured standing wave ratio is lower than the reference level; and f) allowing the standing wave ratio detector to send an alarm signal for antenna fault notification to a base transceiver station if the standing wave ratio of the transmission/reception antenna is determined to be lower than the reference level for fault determination at the step e).